This section provides background information related to the present disclosure which is not necessarily prior art.
Gas turbine engines are typically used in work-generating applications in the form of a rotating drive shaft, and engine control is generally optimized for maximum shaft work per unit of fuel. In these applications bleed air is commonly used with the objective to power accessories or control cycle parameters such as surge. In all of these cases, it is recognized that the bleed air reduces the thermal efficiency of the gas turbine in terms of shaft work per unit fuel. This efficiency loss is typically addressed by using a “bleed-less” engine technology.
Recent efforts have shown that gas turbine engines can be useful in heat generation applications. In particular, a small gas turbine engine has proven to be relatively trouble-free and extremely efficient such that it makes an excellent heater. Such a heater application is different from the conventional work-generating applications in that the efficiency objective is heat output rather than shaft work. As such varying the bleed air to control heat output certainly changes the energy balance of the system but results in no loss of efficiency since any shaft work loss is turned into useful heat.
Accordingly, it is desirable to provide a method to bleed turbine compressor air for controlling the exhaust gas temperature of a gas turbine heater. In addition, it is desirable to a control algorithm for bleeding turbine compressor air to control the exhaust gas temperature of a gas turbine heater. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.